Navigating the Inland Waterways: Charts & Resources | Quimby's Cruising Guide

If you’ve spent any time at all on the inland rivers and lakes of the United States, then you know that boating here is different. The scenery and atmosphere are different. The water and weather are different. Even the boats and some of the boating rules are different. These differences are a big part of what makes cruising in mid-America so appealing, and challenging.

In this article, we cover the fundamentals of safely navigating our inland waterways. Remember that you must adjust to the conditions; they will not adjust to you. The good news is that with a little practice, patience and good judgment almost anyone can enjoy the thousands of miles of amazing cruising available in our country’s interior.

Charts & Other Resources

The use of a chart is recommended at all times unless you are very familiar with the body of water on which you are traveling. The Army Corps of Engineers is responsible for maintaining the navigable inland waterways, and its charts are available by river and/or river section. They can be purchased as printed sets or downloaded for free online. You’ll see that these charts are marked in river miles, starting with 0 at the mouth of the river and increasing to the headwaters. Specific sites on the rivers are labeled pertaining to their downstream location. So, a marina or lock that is labeled “Mile 5 right descending bank” (or RDB) will be on your starboard if you are headed downstream, but on your port if you are headed upstream.

It’s also recommended that you get a copy of Navigation Rules, International-Inland, the Coast Guard publication that includes regulations governing the inland waterways. You can probably purchase the book, along with charts for every inland river, for the price of what it would cost to replace one propeller. Water levels can change dramatically on the inland rivers and lakes due to heavy rain, or lack thereof, and it’s a good idea to ensure that you have enough clearance above and below your boat to get where you need to go. Up-to-date river levels and forecasts can be viewed online at http://water.weather.gov/ahps/forecasts.php and http://mvs-wc.mvs.usace.army.mil/dresriv.html.

Water Conditions

High Water floods the downtown riverfront area of Davenport Iowa in 2019

With the exception of the Tennessee and the Cumberland rivers, which flow south to north, the inland waterways flow from north to south. Locks and dams are used to regulate the water conditions and help maintain a uniform depth in the navigation channels (typically 9 feet). These channels can be hundreds of feet wide, with the current only a few miles per hour under normal circumstances. The shallower water on both sides of the channel is often deep enough for pleasure craft. This means that, using caution, almost the entire surface of the rivers and the lower reaches of many of the larger tributaries are accessible.

For normal running, you should stay in the main channel shown by the sailing line on the navigation charts. In straight sections of the river, the channel is usually in the center. Where the river bends, however, the current swings wide and the outside of the curve will have deeper water. On the inside, sand and silt will build, creating shoals. For this reason, it is poor practice to cut across the bends in rivers. Anywhere the water’s flow is restricted or runs slower, a sandbar is likely to build up. You can expect shoals not only on the inside of bends, but also at the upstream and downstream ends of islands, above and below dams, and near the mouths of tributaries.

The bank itself can be a good indicator of the water depth. Along a high, steep bank you can expect deep water almost to the shoreline. But where a low sloping beach runs back a long way from the water’s edge, the bottom will have a similar slope and may be shallow as much as 200 feet from shore. Besides knowing where to expect shallow water, it’s also an advantage to be able to detect it. Shallow water may often be revealed by a difference in the color of the water, by riffles when the rest of the river is calm or by a patch of quieter water when the rest is choppy.

For procedures on anchoring, please reference our “Anchoring along the Inland Waterways” article

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